LittleBigPlanet

At one point in our demonstration of LittleBigPlanet, someone asks a simple question about the physical interaction of the materials you can use to create stuff in its sticky-back-plastic platform-game world. It's answered, wordlessly, by level designer Dan Leaver. In a minute or two, he creates a constellation of blocks of concrete, wood and sponge hanging in mid-air. Then he exits edit mode - effectively un-pausing the game - and they crash to earth convincingly, tumbling, bouncing and squashing each other.

Then someone else asks an equally innocuous question about whether heavy blocks will kill the game's little cloth-puppet avatars, the sackboys. The short answer is yes, but the long answer - the ten-minute-long answer - involves Leaver, from developer Media Molecule, and Sony producer Pete Smith getting embroiled in an absurdly convoluted attempt to prove it. Leaver's sackboy creates a gigantic set of stairs and carefully balances a giant concrete block on the top of it. Smith uses his sackboy to attach a weighted rope to the block. They start the level (several times - the block keeps falling off too soon). Leaver climbs the steps and pushes, while Smith grabs the weight and pulls in an effort to kill his sackboy in a slapstick-assisted suicide.

It doesn't work. It doesn't matter. They're clearly having fun - more fun than we are, it must be said. They bounce ideas and comments around, suddenly oblivious to the presence of half a dozen perplexed and slightly bored games journalists. That's because, contrary to what some people are saying, LittleBigPlanet isn't designed to be observed by hacks and discussed on their trendy, buzzword-brandishing blogs. It's designed to be played, and played with, by everyone. Based on our short demonstration and playtest - and the ridiculous antics of Smith and Leaver - the pull to play with it is wholly irresistible.

Imaginative, artistic, challenging, begging to be knocked over.

It's funny that a game that makes such blissful sense when you see it in person can be so hard to explain in words. It's also true that, in the rush to talk about its content-creation side, it's easy to forget to cover the basics, so let's start there. LittleBigPlanet is a side-scrolling platform game. It lets up to four players, online or local, romp through its knockabout assault-courses and mini-games in a happy scramble of competition and co-operation.

You can also use LittleBigPlanet to make stuff. Not just your own levels for the game - any stuff. A giant ball-pool to play in with your friends - that would take about five minutes. A sort of interactive toy website, maybe featuring your holiday photos or links to favourite LittleBigPlanet levels by other creators, might take an hour or two. A giant, hideous effigy of one of your friends and a piston-driven canon that fires sponge frying pans at his wobbly head: two or three hours. A full-size, meticulously-designed platform game level with an "Early Learning Centre does Salvador Dali does Flash Gordon" theme: a week, a month... how long have you got?

The easiest way to make shapes is by cutting out from the edges.

You might not want to do any of that, but somebody will, and it'll be there on PSN for you to download and play, making LittleBigPlanet the platform game with no end. Sony's vision is of a never-ending stream of stuff to play, filtered and sorted by the networking, aggregating and tagging systems familiar from the likes of YouTube.

It's all summed up beautifully by the game's main interface screen - so beautifully, we probably should have started there. Sackboy is in his cardboard-box space station with his giant PS3 controller (labelled "Puter"), looking down at the little big planet and its moon - "My Moon". The planet is labelled "story" (we're assured that there is one, sort of, but it's not very important). It has tens of themed level hubs with names like "Comrade Sackputin's Bunker", each of which seems to link to a dozen or so levels and mini-games. This, it's becoming apparent, will be a big game even if you never download or create a thing for it.